A Republican plan to rein in the rising cost of Social Security would dramatically reduce retirement benefits for middle- and upper-income Americans, especially those now younger than 25, according to an analysis released Wednesday by the program's chief actuary.

The plan, by Rep. Paul Ryan (R-Wis.), would reduce benefits by gradually raising the retirement age and gradually trimming benefits for the top 70 percent of earners.

Together, the two provisions would slice initial benefits by about a quarter for middle-income Americans who turn 65 in 2050, according to the analysis. Wealthier retirees would see even deeper cuts, losing about a third of scheduled benefits in 2050 and more than half of scheduled benefits if they turn 65 in 2080.

With congressional elections less than two weeks away, the Ryan plan has been a frequent target for Democrats accusing the GOP of plotting to gut Social Security. But the report by Stephen Goss, chief actuary for the Social Security Administration, also examines other ideas for overhauling the program, including several under discussion by a bipartisan deficit-reduction commission appointed by President Obama. Leaders in both parties say Social Security may present the best opportunity for compromise on the commission, which is due to issue a report Dec. 1.

Goss's analysis shows that those ideas may not be much more palatable than Ryan's plan. For example, allowing the retirement age to continue rising two months per year until it hits age 70 would cut initial benefits by nearly 20 percent for anyone turning 65 in 2050. Meanwhile, the commission is talking about trimming the cost-of-living increase retirees receive each year, as well as cutting their initial benefits.

"There's been a lot of discussion about how easy it would be to cut Social Security in order to save it," said Rep. Earl Pomeroy (D-N.D.), who requested the report as chairman of the House Ways and Means subcommittee on Social Security. "The new analysis reveals that these proposals result in benefits cuts ranging from 10 percent to as high as 50 percent. . . . That's not what I'd call 'saving' Social Security."

Ryan spokesman Conor Sweeney said Goss did not analyze the full effect of Ryan's plan to balance the federal budget and ignored Ryan's proposal to guarantee a higher minimum benefit to low-income retirees. More to the point, Sweeney said, failing to overhaul Social Security - which is already paying out more than it collects from payroll taxes - will cause more immediate harm.

"According to the Social Security Administration, Congressman Pomeroy's do-nothing plan will impose painful, across-the-board benefit cuts on current seniors and those nearing retirement," Sweeney said. "It is deeply irresponsible for elected leaders to stand idle with icy indifference as the social safety net collapses."